Refrigerating apparatus



Feb. 2, 1943. c. A. STICKEL.

RFRIGERATING APPARATUS Fi'led Aug. 20, 1941 al; f4?

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//H////// /f ///////////0//N//// /f/ 3m/f /f/ /W /Vf Patented Feb. 2,1943 REFRIGERATING APPARATUS Carl A. Stickel, Dayton, Ohio, assignor toGeneral Motors Corporation, Dayton,

tion of Delaware Ohio, a corpora- Application August 20, 1941, SerialNo. 407,621

Claims.

This invention relates to refrigerating apparatus and particularly to atwo-temperature :refrigerator cabinet. o

.An object of my invention is to provide an improved two-temperaturerefrigerator' cabinet.

Another object of my invention is to provide an improved and moreefficient manner of refrigerating a two-temperature refrigerator cabinetof the type wherein a portion of a secondary refrigerant circuit isassociated with a part of a primary refrigerating system and is employedto cool the interior of the uppermost compartment of superimposedcompartments in the refrigerator cabinet.I

A further object of my invention is to associate a primary refrigeratingsystem, having two evaporators disposed one above the other, with atwo-compartment refrigerator cabinet wherein the lowermostof theevaporators is employed to cool the lower compartment of the cabinet,and the other or uppermost evaporator is utilized to render a, closedsecondary refrigerant circuit elective to cool the upper compartment ofthe cabinet and to provide the primary refrigerating system with amultiple effect compressor for withdrawing refrigerant directly andsimultaneously from both primary evaporators to thereby maintain thetemperature differential between the two compartments substantiallyuniform.

A still further and more specific object of my invention is to provideforl the detachment of the primary evaporator in a system of the typedescribed in the preceding object from the condensing portion of thesecondary refrigerant circuit and for the removal of the primaryrefrigerating system as a unit from the cabinet.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawing, wherein a preferred form of the present invention is clearlyshown.

In the drawing:

Fig. 1 is a vertical sectional view of a refrigerator cabinet having myinvention embodied therein; and

Fig. 2 is a diagrammatic showing of the refrigerating systems associatedwith the refrigerator cabinet disclosed in Fig. 1.

Referring to the drawing, for illustrating my invention, I have shown inFig. 1 thereof a'refrigerating apparatus of the. two-temperature CIIhousehold type. A cabinet I0 has aplurality of outer metal panels orwallsfII and'jan inner'.

Any suitable or desirable insulating material I3 is disposed between theliner I2 and walls II of cabinet I0 to insulate the chamber therein.Liner member I2 has an aperture therein regis` tering with an apertureformed in the front wall II of cabinet I0 to provide an access openingfor the chamber. Breaker strips I4 of any Vsuitable or desirableinsulating material overlap the edge portion of the aperture in thecabinet -front wall and the spaced edge portion of the aperture in linerI2 to provide walls of the access opening. These breaker strips I4 areremovably secured in place in any convenient or conventional manner fora purpose to become apparent hereinafter. The chamber within cabinet I 0is divided into an upper food storage compartment I6 and a lower foodstorage or freezing' compartment II by a. removable glass plate or thelike partition I8. Partition I8 has a rubber or the like gasket memberI9 secured to all four edges thereof, and the gasket I 9 engages thethree vertical walls of liner I2 and the inner face of an insulated doorstructure 2I which normally closes the access opening to the cabinetchamber. The engagement of gasket ,I9 with walls of liner I2 and thedoor 2l causes partition I8 to isolate the compartments I6 and I1 fromone another. The outer cabinet walls II depend below the insulatedchamber and form a machine compartment 22 in the bottom of therefrigerator cabinet for housing a. refrigerant liquefying andcirculating unit of a primary refrigerating system. An opening providedin the front of the machine compartment 22, for a purpose to behereinafter described, is closed by a cover or door 23.

The primary refrigerating system associated with the refrigeratorcabinet I0 includes a rst evaporator in the form of a conduit loop 2Bwhich is disposed in the insulation I3 at the top of cabinet I0, underthe breaker strip I4, and another or second evaporator 2l located belowthe rst evaporator 26 and disposed within the lower compartment I1.Evaporator 2'I is preferably of the sheet metal U-shaped variety whereinrefrigerant expansion passageways are formed intermediate two securedtogether metal plate members. The refrigerant liquefying andcirculatingV unit of the primary refrigerating system is mounted in themachine compartment 22 and lcomprises a sealed motor-compressorv unit 28.and` ia, condenser 29. In the present disclosure, fthe compressor 3l ofunit 28 (see Fig metalliner member I2 spaced therefrom and Y formingwalls of a chamber withinthe cabinet."y

192,846, filed February 26, 1938. This compressor 3| has separaterefrigerant gas return conduit connections 32 and 33, with each of theevaporators 26 and 21 respectively for simultaneously withdrawingrefrigerant therefrom. Refrigerant compressed by the compressor 3i ofunit 28 is forwarded under pressure, through a pipe 34, to condenser 26where it is cooled and liquefied in any suitable or desirable manner.The liquid refrigerant is circulated to the upper or irst evaporator 26by way of a long smalldiametered pipe 36 which restricts or controls theflow of refrigerant into evaporator 26. Restrictor pipe 36 is connectedto a depending end portion 31 of the larger conduit 26 of the upperevaporator, and some of the refrigerant upon entering this evaporatorbegins to evaporate while the remainder thereof stays in liquid form andis conveyed to the lower or second evaporator 21 by way of another long,small diametered pipe 38. Pipe 38 extends into the end portion 31 ofevaporator 26 and communicates with the open end of pipe 36. This pipe36 restricts or controls the feeding of liquid refrigerant fromevaporator 26 into evaporator 21. 'I'he expanding or evaporatingrefrigerant entering the conduit evaporator 26 causes same to produce arefrigerating effect for a purpose to be hereinafter described.Refrigerant expanding into or evaporating within the lower or secondevaporator 21 causes this evaporator to produce a refrigerating effectto cool the lower compartment I1. The temperature of evaporator 21 is atall times maintained below freezing in order to freeze water or othersubstances placed in trays and adapted to be located. thereon. Thecooling of compartment I1 at such lowA temperature causes frost to formon walls of the primary evaporator 21, which also causes dehydration ofthe air within the compartment and the maintenance of a low relativehumidity therein. Starting and stopping of the electric motor of themotorcompressor unit/26 may be carried out in response to thetemperature produced by evaporator 21. Thus, I locate a thermostaticbulb 4I within compartment I1 adjacent a wall of evaporator 21 andconnect this bulb, by a pipe 42, with an expansible and contractablebellows 43 forming part of a snap-acting control switch 44 (see Fig. 1).Switch 44 is conventional and controls an electric circuit to the unit28 to start and/or stop operation of the electric motor and consequentlythe multiple effect compressor 3I of the primary refrigerating system.

A closed secondary circuit containing a volatile liquid refrigerant isassociated with the refrigerator cabinet I6 and comprises a refrigerantcondensing portion 46 in the form of a conduit thermally contacting theupper evaporator 26 of the primary refrigerating system. Removableclamping means (not shown) may, if desired, be utilized for holding thecondenser portion 46 of the secondary circuit in intimate thermalcontact with the primary evaporator 26. A liquid feeding conduit 41 isconnected with the condensing portion 46 of the secondary circuit andextends downwardly therefrom for feeding condensed liquid refrigerant toan evaporating portion 48 of the secondary circuit. The evaporator orevaporating portion 48 of the secondary circuit comprises a plurality ofconduit loops secured to and extending over the outer surfaces of linerf asoavsv trap 46 formed therein connects the evaporating portion orloops 48 of the secondary circuit with the condenser 46 thereof as iscustomary in such systems to cause all liquid condensing in condenser 46to drain directly into the feeding conduit 41. It will be noted that thegreater portion of the secondary circuit is disposed below the level ofthe first or upper evaporator 26 of the primary refrigerating system andthat the refrigerant evaporating portion 46 of thesecondary circuit islocated above the second or lower primary evaporator 21. Volatilerefrigerant evaporating within the portions 48 of the secondary circuitcools the walls of the upper food storage compartment I6 of cabinet I8and maintains the interior of this compartment at a temperature abovefreezing to thus minimize convection currents therein. The interior ofcompartment I6 is maintained between certain temperature limits inaccordance with the normal temperature limits of the primary evaporator21 by association of condenser 46 of the secondary refrigerant circuitwith evaporator 26. When refrigerant is withdrawn from evaporator 21 bythe multiple effect compressor 3|, refrigerant is also withdrawn fromevaporator 26 to render the evaporating portion of the secondary circuiteffective to cool compartment I6. Refrigerant, after evaporating andflowing upwardly in the loops 48 of the secondary circuit enters thecondenser 46 by way of trap 49. This evaporated refrigerant is condensedand liquefied by the refrigerating effect or low temperature of theupper primary evaporator 26 and the liquefied refrigerant then flowsdownwardly from condenser 46 by way of the liquid feeding conduit 41 tothe lowermost evaporating loops 46. In a structure of the typedisclosed, it is the purpose of parti-l tion I8 to divide the cabinetchamber into two compartments wherein the one or lower compartment I1 ismaintained at a low or freezing temperature and low relative humidity inthe' manner described and wherein the other or upper compartment ismaintained at a higher temperature and consequently high humidity forproviding a two-temperature cabinet for the storage of various foodproducts.

The multiple effect compressor 3l of the primary refrigerating systemwithdraws low pressure refrigerant, by way of conduit 33, fromevaporator 21 and at the same time withdraws high pressure refrigerant,by way of the separate conduit 32, from the upper evaporator l26. Theuse of the multiple effect compressor in a system of the type disclosedprovides for more efficient handling of the refrigerant of the primarysystem and provides quicker response of the secondary refrigerantcircuit to cool the high temperature, high relative humidity compartmentI6 and thereby maintains a more uniform temperature therein. As shown inFig. 2, it will be noted that the low suction pressure port entering thecompressor 3I from conduit 33 is disposed in close proximity to thecompressor blade while the relatively higher suction pressure portentering the compressor from conduit 32 is disposed at an angle theretoas is customary in conventional multiple eifect compressors. Thus, byproviding the primary refrigerating system with separate gaseousrefrigerant return conduits and by connecting these conduits with amultiple effect compressor, refrigerant is simultaneously withdrawn fromthe primary evaporators 26 and 21 to thereby render the secondaryrefrigerant circuitmore directly responsive to cooling produced bytheprimary Vrefrigerating system. p

In tliegpresent structure I have located the conduits 26, 32, 33, 36 and38 of the primary refrigerating system in the. front portion of cabinetl vso as toprovidefor the removal of the primary refrigerating system asa vunit outwardly from thefront of` the cabinet. For exf ample, theconduitsrfare disposedin the insulation I3 directlybeneath the dooropening breaker strips orwallsiM-.alongfa side and the top vof thelaccess 1: e l stantially'injthe--manriershovvrr and describedV ningtoVthecabinet chamber subin: the v McCormack-et all; Patent No. 2,010,924

'dated August i l3`,fl'93;5 upon detachment fofy the chainber*access-`opening walls'flfrom the cabinet,v access` ma'yfbeV had to, thevconduits 26, V32,- 33, 36 and 38. to withdraw theseconduits through thespacev between" the outer wall Il andliner I2 so that they may beremoved along with the evaporator 21 and'unit28'of the pri-` maryrefrigerating system outwardly from the front of the cabinet. Inremoving the elements of the primary refrigerating system as a unit fromcabinet l0, the electric wires intermediate switch 44 and unit 28 aredisconnected to enable switch 4d to remain in the cabinet. Any damage orinoperativeness of the primary refrigerating system can readily beremedied by the removal thereof from the cabinet and the replacementinto the cabinet of another unit or system as is customary inpresent-day installations.

From the foregoing it will be apparent that I have provided an improvedand more efiicient' lower of the compartments of the refrigeratorcabinet and by simultaneously withdrawing refrigerant from both primaryevaporators through separate conduit connections with a multiple effectcompressor. The contact between the one primary evaporator and thecondenser of the secondary circuit is predetermined to thereby insurethe maintenance of a substantially constant temperature and highrelative humidity within the higher-temperatured upper storagecompartment of the cabinet.

While the form of embodiment of the invention as herein disclosed,constitutes a preferred form, it is to be understood that other formsmight be adopted, all coming within the scope of the claims whichfollow.

What is claimed is as follows:

1.I A refrigerating apparatus comprising in combination, a cabinethaving an upper food storage compartment and a lower food storagecompartment therein, a closed primary refrigerating system including afirst evaporator in the upper part of said cabinet and a secondevaporator disposed in heat exchange relationship with said lower foodcompartment for cooling same, a closed secondary refrigerant circuitcontaining a volatile liquid and including acondensing portion inintimate heat exchange relationship with said rst primary evaporator andan evaporating portion located therebelow and disposed in heat exchangerelationship with said upper food compartment for cooling same, fconduit means for conveying refrigerant f roin said first primaryevaporator to said secondl pril mary evaporator. and said primaryrefrigerating system including a multiple effect compressor havingseparate conduit connections with each of said evaporators thereofrigerant directly therefrom.

y 2. A refrigerating apparatus *comprising* combination, a cabinethaving anI upper food.,

storage compartment and avlower food storage compartment therein, aclosed primary refrigerating system-'including-a first evaporatorin theupper part of said cabinet -and a second evap orator disposedwithinfsaid lower food compartment for cooling same, a closedsecondaryrefrigerant circuit :containing a volatile liquid and including acondensingfportion in intimate heat exchange relationship'with saidfirst primary evaporator and an evaporating portion located..

therebelow and disposed in intimate thermal contact with walls of saidupper compartment forcooling the interior thereof, conduit means forconveying refrigerant from said first primary evaporator to said secondprimary evaporator,

and said primary refrigerating system including y a multiple effectcompressor having separate conduit connections with each of saidevaporators thereof for withdrawing refrigerant directly therefrom.

3. A refrigerating apparatus comprising in icombination, a cabinethaving a plurality of walls forming a chamber therein, said chamberbeing provided with an access opening normally closed by a door. meanscooperating with the `inner face of said door and with the uprightwallsof said chamber for dividing the chamber into an upper food storagecompartment and a lower food storage compartment, a closed primaryrefrigerating system including a rst evaporator in the upper portion ofsaid cabinet and a second evaporator disposed in heat exchangerelationship with said lower food compartment for cooling same, a closedsecondary refrigerant circuit containing a volatile liquid and includinga condensing portion in intimate heat exchange relationship with saidfirst primary evaporator and an evaporating portion located therebelowand disposed in heat exchange relationship with i ating system includinga multiple effect compressor having separate conduit connections witheach of said evaporators thereof for withdrawing refrigerant directlytherefrom.

4. A refrigerating apparatus comprising in combination, a cabinet havinga plurality of walls forming a chamber therein, said chamber beingprovided with an excess opening normally closed by a door, removablemeans cooperating with the inner face of said door and with the uprightwalls of said chamber for dividing the chamber into an upper foodstorage compartment and a lower food storage compartment, a closedprimary refrigerating system including a first evaporator in theupper'portion of said cabinet and a second evaporator disposed withinsaid lower food compartment for cooling same, a closed secondaryrefrigerant circuit containing a volatile liquid and including acondensing pori for withdrawing rev-2v tion in intimate heat exchangerelationship with said first primary evaporator and an evaporatingportion located therebelow and disposed in intimate thermal contact withwalls of said upper compartment for cooling the interior thereof,conduit means for conveying refrigerant from said first primaryevaporator to said second primary evaporator, and said primaryrefrigerating system including a multiple effect compressor havingseparate conduit connections with each 10 oi' said evaporators thereoffor withdrawing refrigerant directly therefrom.

l5. A refrigerating apparatus comprising in combination, a cabinethaving an upper food storage compartment and a lower food storagecompartment therein, a closed primary refrigerating system including afirst evaporator in the upper part of said cabinet and a secondevaporator disposed in heat exchange relationship with said lower foodcompartment for cooling same, a closed secondary refrigerant circuitcontaining a volatile liquid and including a con-y densing portion inintimate heat exchange re lationship with said first primary evaporatorand an evaporating portion located therebelow and disposed in heatexchange relationship with said upper food compartment for cooling same,and said primary refrigerating system including a multiple eiectcompressor having separate conduit connections with each of saidevaporators thereof for withdrawing refrigerant directly 15 therefrom.

CARL A. BTICKEL.

